Technical information

Part No. T0289, Rev A
August, 2008
Known Software Limitations Page 17 of 97
Known Software Limitations
Introduction This section lists limitations known to exist in Release 7.1.R00A Applications Ware
software.
RTP Header
Compression
RTP Header Compression Interoperability Between Cisco and
Vanguard Networks Products over Frame Relay Limitations
Incompatible Cisco Features- There are a few Cisco proprietary features that must be
disabled in order to ensure proper interoperability over Frame Relay links. The table
below identifies the incompatible features.
Protocols Not Supported - Vanguard Frame Relay links configured for CENCAP
encapsulation do not support Transparent Bridging traffic.
Configuration - The “Number of Session to be Compressed” parameter must not be
configured to a value greater than 255 when the encapsulation is configured to
“CENCAP”. Cisco products are limited to 8-bit Context Identifiers (CIDs) over
Frame Relay. Configuring a Vanguard node for more than 255 sessions will cause it
to use 16-bit CIDs.
Descriptions Incorrect FXO RX Disconnect Timer can lock FXO port (CR16670)
When the FXO RX Disconnect Timer is shorter than the the PBX power interrupt,
then the FXO port can lock up requiring a cold boot to reset.
Workaround: Make the FXO Rx Disconnect Timer greater than the longest PBX
power interrupt.
Vanguard Software Builder: Does not show warning when 342 and
342v3 Selected Option Size/Estimated Free Flash Space exceeds
8Mbytes (CR16872)
Workaround: Visually check that Selected Option Flash size does not exceed 8
Mbytes.
Feature Comments
tcp header-compression Vanguard Networks products do not support tcp
header compression over Frame Relay. TCP header
compression must be disabled on Cisco Frame
Relay interfaces.
Frame relay end-to-end
keepalives
Encapsulation for keep alive packets is Cisco
proprietary and as a result is not supported on links
between Vanguard Networks and Cisco nodes.
Cisco discovery protocol CDP must be disabled on links connected to
non-Cisco devices.